What is the most likely diagnosis for calf pain with difficulty in dorsiflexion but minimal pain with plantarflexion after a traumatic injury while playing pickleball?

Most Likely Diagnosis: Medial Gastrocnemius Strain (Tennis Leg)

Your presentation is classic for a medial gastrocnemius muscle strain, commonly called "tennis leg"—the sudden sensation of being struck in the calf during activity, preserved plantarflexion with minimal pain, but difficulty with dorsiflexion that stretches the injured muscle. 1, 2

Clinical Reasoning

Why This Is a Gastrocnemius Strain

• The "pop" or "ball strike" sensation during athletic activity is pathognomonic for acute gastrocnemius injury, representing the moment of muscle fiber disruption 1, 3

• Pain with dorsiflexion but minimal pain with plantarflexion is the key distinguishing feature: dorsiflexion stretches the gastrocnemius (especially when the knee is extended), while plantarflexion contracts it but doesn't stress torn fibers as severely 1

• The medial head of the gastrocnemius is the third most commonly strained muscle in elite athletes and the most frequently injured calf muscle overall 3, 4

• Pickleball involves rapid directional changes with the ankle in plantarflexion and knee extended—the exact biomechanical position that predisposes to gastrocnemius strain when sudden dorsiflexion force is applied 1

Anatomical Location

• Two-thirds of gastrocnemius injuries occur at the musculotendinous junction between the medial gastrocnemius and soleus (the fascial plane), though injury can occur anywhere from proximal origin to mid-belly 3, 4

• The medial head is preferentially injured in 95% of isolated gastrocnemius strains compared to the lateral head 4

Expected Physical Examination Findings

• Antalgic gait with shortened stance phase on the affected side 1

• Ecchymosis and swelling in the posteromedial calf (may develop over 24-48 hours) 1

• Local tenderness over the medial gastrocnemius, potentially with a palpable gap if severe (Grade III) 1

• Positive Thompson test would be negative (distinguishes from Achilles rupture—you can still plantarflex) 1

• Pain reproduced by passive ankle dorsiflexion with knee extension (stretches the gastrocnemius maximally) or resisted plantarflexion with knee extended 1

Differential Diagnosis to Exclude

Achilles Tendon Rupture

• Would present with inability to plantarflex or significant weakness, not "minimal pain with plantarflexion" 1
• Positive Thompson test (no plantarflexion with calf squeeze) 1
• Your preserved plantarflexion essentially rules this out

Deep Vein Thrombosis

• Would have pain at rest, not just with dorsiflexion 5
• Entire leg involvement with persistent swelling, not localized to muscle belly 5
• No acute "pop" sensation during activity 5

Soleus Strain

• Pain would be present with plantarflexion (soleus is a pure plantarflexor) 4
• Less common as isolated injury (46% vs 49% for gastrocnemius in one series) 4
• Your minimal pain with plantarflexion makes isolated soleus strain unlikely

L5 Radiculopathy

• Would have chronic or subacute onset, not acute traumatic "pop" 6
• Neurological findings (weakness, sensory changes, reflex abnormalities) 6
• No direct correlation with specific athletic movement 6

Diagnostic Approach

Clinical Diagnosis Is Sufficient

• Diagnosis is primarily clinical based on history and physical examination 7, 1
• The classic presentation you describe (acute pop, dorsiflexion pain, preserved plantarflexion) is diagnostic 1, 3

When to Consider Imaging

Ultrasound is the preferred initial imaging modality if confirmation needed: 3

• Provides real-time dynamic assessment 3
• Can grade injury severity (Grade I-III) 3
• Identifies location within the musculotendinous unit 3
• Monitors healing progression 3

MRI is reserved for: 1, 4

• Uncertain diagnosis after clinical evaluation 1
• Suspected complete (Grade III) rupture requiring surgical consideration 1
• Dual muscle injuries (gastrocnemius + soleus occur in 60% of dual injuries) 4
• Failure to improve with conservative management 1

Timing of Reassessment

• Reexamine 3-5 days after injury when swelling has improved to accurately distinguish partial tears from complete ruptures and finalize grading 7

Common Pitfalls to Avoid

• Don't assume all calf pain is "just a strain"—always assess for DVT risk factors, especially in older patients or those with prolonged immobility 5

• Don't miss dual injuries: 34% of calf strains involve more than one muscle (most commonly gastrocnemius + soleus), which may affect prognosis and recovery time 4

• Don't overlook high ankle (syndesmotic) involvement: though your symptoms point to muscle injury, always palpate the syndesmosis and perform a crossed-leg test if there's any anterior ankle pain 7

• Chronological age and previous calf injury are the strongest risk factors for gastrocnemius strain—document these for prognostication 1